Android 2.3 Gridview with BaseAdapter in AlertDialog

LOS LAYOUTS
In the layout section of the project, right click, option New and then Layout Resource File
ACTIVITY MAIN (Main activity)

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/btnAlerta"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="MosAlerta"
        android:text="Mostrar alerta con GridView" />
</RelativeLayout>

THE ITEM FOR THE GRIDVIEW (Location of objects in each gridview item)
item_grid.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:padding="1dp"
    android:orientation="vertical"
    >

    <LinearLayout
        android:layout_width="90dp"
        android:layout_height="90dp"
        android:layout_margin="2dp"
        android:background="@drawable/bordes"
        android:orientation="vertical"
        android:padding="2dp">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@drawable/fondo"
            android:orientation="vertical"
            android:padding="2dp">

            <TextView
                android:id="@+id/lblNombre"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:gravity="center_vertical|center_horizontal"
                android:text="Titulo"
                android:textSize="14dp"
                android:textStyle="bold" />

            <ImageView
                android:id="@+id/imgFoto"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:padding="5dp"
                android:src="@mipmap/ic_launcher" />

        </LinearLayout>
    </LinearLayout>

</LinearLayout>

THE GRIDVIEW (griview object to be embedded in the alert)
grid_alerta.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/idGAlert"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="?android:attr/colorBackground"
    android:orientation="vertical">

    <TextView
        android:id="@+id/lblTitu"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:text="Titulo de mensaje"
        android:textAlignment="center"
        android:textSize="20sp"
        android:textStyle="bold" />

    <TextView
        android:id="@+id/lblSubtitu"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginBottom="10dp"
        android:text="SubTitulo de mensaje"
        android:textAlignment="center"
        android:textSize="16sp"
        android:textStyle="italic" />

    <GridView
            android:id="@+id/grdGrilla"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:listSelector="@color/colorPrimary"
            android:columnWidth="80dp"
            android:numColumns="auto_fit" >


    </GridView>

</LinearLayout>

LOS DRAWABLES
Should be placed in the drawable section of the NO EN LAYOUT project, they determine the style (border and background) of each grid item.

edges.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:state_pressed="true"><shape>
        <solid android:color="#cccccc" />
    </shape></item>
    <item><shape>
        <gradient
            android:angle="270" android:endColor="#ccc"
            android:startColor="#fff" />
        <corners android:radius="2dp" />
    </shape></item>

</selector>

fondo.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:state_pressed="true"><shape>
        <solid android:color="#cccccc" />
    </shape></item>
    <item><shape>
        <gradient android:angle="90" android:endColor="#f5f5f5" android:startColor="#fff" />
    </shape></item>

</selector>

THE ADAPTER
clsAdaptadorGrid.java

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class clsAdaptadorGrid extends BaseAdapter {
    Context Contexto;
    String[] Nombre;
    int[] Foto;
    LayoutInflater inflater;
    public clsAdaptadorGrid(Context cContexto, String[] cNombre, int[] cFoto)   {
        this.Contexto = cContexto;
        this.Nombre = cNombre;
        this.Foto = cFoto;
    }
    @Override
    public int getCount()
    {
        return Nombre.length;
    }

    @Override
    public Object getItem(int position)
    {
        return null;
    }

    @Override
    public long getItemId(int position)
    {
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent)    {
        TextView xNombre;
        ImageView xFoto;

        inflater = (LayoutInflater) Contexto.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View itemView = inflater.inflate(R.layout.item_grid, parent, false);

        xNombre = (TextView) itemView.findViewById(R.id.lblNombre);
        xFoto = (ImageView) itemView.findViewById(R.id.imgFoto);

        xNombre.setText(Nombre[position]);
        xFoto.setImageResource(Foto[position]);
        return itemView;
    }
}

THE MAIN ACTIVITY MainActivity.java

import android.app.AlertDialog;
import android.content.DialogInterface;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.AdapterView;
import android.widget.GridView;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    AlertDialog iconDialog;
    int Elemento;
    String[] aNombres = {"Juan","Carlos","María","Nadia","Perla"};
    int[]    aFotos   = {R.mipmap.ic_launcher,R.mipmap.ic_launcher,R.mipmap.ic_launcher,R.mipmap.ic_launcher,R.mipmap.ic_launcher};
    clsAdaptadorGrid Adapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
    public void MosAlerta(View v){
        Elemento=-1;
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        Adapter = new clsAdaptadorGrid(this, aNombres, aFotos);

        LayoutInflater inflater = this.getLayoutInflater();
        View ViewAlerta = inflater.inflate(R.layout.grid_alerta, null);
        GridView xGrilla = (GridView) ViewAlerta.findViewById(R.id.grdGrilla);
        TextView xTitulo = (TextView) ViewAlerta.findViewById(R.id.lblTitu);
        TextView xSubti = (TextView) ViewAlerta.findViewById(R.id.lblSubtitu);

        xGrilla.setAdapter(Adapter);
        xGrilla.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Elemento = position;
                iconDialog.getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(true);
            }
        });
        xTitulo.setText("Usuarios bloqueados");
        xSubti.setText("Fíjate bien si estás en la lista");

        builder.setView(ViewAlerta);
        builder.setCancelable(false);
        builder.setPositiveButton("Seleccionar", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                String sNombre = aNombres[Elemento];
                Toast.makeText(getApplicationContext(), "Nombre: " + sNombre + " (item: "+Elemento+")", Toast.LENGTH_SHORT).show();
            }
        });
        builder.setNegativeButton("Cerrar", null);

        iconDialog = builder.create();
        iconDialog.show();
        iconDialog.getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(false);
    }
}

THE CAPTURES